big bang, black holes, no math astr/phys 109 dr. david toback lecture 20 & 21

Big Objects and Black HolesTopic 1: Galaxies

Big Bang, Black Holes, No Math 1

Big Bang, Black Holes, No MathASTR/PHYS 109

Dr. David TobackLecture 21 & 22



Was due Today – L22• Reading:

– (Unit 5)• Pre-Lecture Reading Questions:

– Unit 4 Revision (if Desired), Stage 2: Due before class today

– Unit 5, Stage 2: Due before class today• End-of-Chapter Quizzes:

– Chapter 14• Papers:

– Paper 2 Revision (if desired), Stage 2: due before Class today

– Paper 3, Stage 2: due before class today• Honors Papers:

– Stages 1 & 2 must be approved explicitly– Final paper due on the last day of class



Quick Review: Various Times

Walking through what happens during each of a number of different periods in time–The VERY early universe–The first three Minutes–The next 300,000 years–The next billion years–~13 billion years later (now)–The ultimate fate

of the universe?

} Chap 14} Chaps 15-17} Unit 6

} Chap 13



Unit 5 Overview•It turns out that the way Galaxies and Stars form have similarities… start there•The way stars die depends on the star itself… sometimes they die to form a Black Hole•Black Holes are some of the weirdest things in the Universe… – In many ways the formation of

Black Holes is like the Big Bang in Reverse



Unit 5: Big Objects and Black Holes

1.Galaxies2.Star Birth and

Death•Black Hole

Formation3.Properties of

Black Holes

Today


Big Bang, Black Holes, No Math

Galaxy Formation: Overview•Big picture: What Galaxies “look like”•A gravity dominated Universe allows galaxies to form•When do galaxies form? 6



What do galaxies look like?

All have common properties

1.Stars (produce the light we see)

2.Gas (atoms not in stars)

3.Dark Matter (most of the mass)

7



Visualizing a Galaxy

8

• The light comes from the stars• Most of the mass is Dark Matter

In some ways, Dark Matter

surrounds the stars in a galaxy like the water in

a fishbowl surrounds a fish in the middle of

the bowl.Not exactly the

same… denser in the middle

because of the pull of gravity



Two example “Types” of Galaxies

9

Spiral Galaxy: like the Milky Way

• Bulge in the middle

• Disk on the sides

Elliptical Galaxy:• One giant bulge,

stars are like bees buzzing around the center, biggest galaxies are ellipticals



From the Early Universe to Galaxies

•After about ~3 minutes things are cool enough for nuclei to form

•After ~300,000 years things are cool enough for electrons and nuclei combine to form atoms

•Let’s move to a half a billion years after the bang



Where are we now in the history?

Half a billion years after the bang



A Gravity Dominated Universe

•The gravitational attraction between massive things ONLY makes them move towards each other through space

•Dark Matter and atoms are neutral and massive

•Both are most attracted to the closest place with lots of mass



Wait a Half Billion Years•As the years go by, mass clumps together

•By a half a billion years after the bang, most of the mass is in one of a large number of “clumps”

•Huge numbers of these clumps, each helps form galaxies!



Galaxy Creation Over Time



Galaxy Formation Analogy:People Jumping on a

TrampolineIf two people touch, then will stick together

If they fall they create a big dent in the trampoline (like a dent in space-time)

Once you get that first dent on the trampoline everyone starts falling into

it



More Analogies1. Water being poured into a

bowl and flowing to the bottom

2. Water swirling in a bowl3. Water in a bathtub with

the drain open (and ignoring what happens to the water that goes down the drain) 16



Water Flowing•Think about water moving towards a drain in the bathtub–All falls in quickly can get bubbling at the drain–Falls in slowly Get swirling

•Different types of galaxies can form 17



Stars in Galaxies• Atoms fall towards the center of the

galaxy or orbit around it• Stars form where there are lots of

atoms• Once the atoms form stars there is a

large amount of distance between stars– About 4 light years between us and

our nearest neighbor star– A good exception is binary stars

where two stars formed together• Stars can orbit around the center of the

galaxy



Slow Atoms Outside the Galaxy

Where does the disk of the Milky Way come from?

Lots of atoms moving around, far outside the center of the galaxy



Spinning into Shape•Gravity attracts mass to the densest place–Center of the Galaxy

•As the mass is pulled in, it starts moving slightly around the center

•Why does this happen?



Analogy: Ice Skater•You’ve seen on TV

•Try this at home in a chair that rotates

•Get yourself spinning with your arms and legs stretched out, then pull them in

For those of you who have taken PHYS 218, this is Conservation of Angular

Momentum

Matter far away from the centerSpins slowly

Pull the Matter in Spins faster

Can also think about water falling into a

drain



Dark Matter Vs. Atoms•Dark Matter and Atoms behave differently in galaxies

•When atoms get near each other they can bump into each other like people moving in a movie theater

•Dark Matter is more like two ships passing in the night



Why is there a disk on the outside?

• Focus on the atoms in the outer part of the galaxy… Not very dense out there, so stars don’t form quickly

• As atoms fall toward the center they are like the water from the outer part of a sink– They start bumping into other atoms, change the direction

they are moving• Once enough atoms are going in different directions a swirl

CAN start; atoms moving WITH the swirl can keep moving nicely and can go orbit like a planet around the sun– Like in a sink, an effective swirl can continue– Atoms that try to go into other directions bang into the

swirl and lose energy (fall in, or go off into space)• Eventually, most of the atoms have either fallen in or become

part of the swirl • Eventually, the cloud gets drawn in close enough that the

atoms get close enough that they form stars– Stars just stay in the disk orbit

• Call this the disk



Visualize the processStart right after things start to contract…



Time progressesAs the galaxy contracts, things can start moving very quickly



More time PassesThings start to “flatten out”Said differently, the flay part can continue, but

the non-flat-part bets bumped out of orbit



More time…



Even more time…



Even more time..



Stable GalaxiesThe stuff in this

stable state forms Stars: Call this a Galaxy– Can give us

disk-like rotating galaxies

– Can also form other types like elliptical galaxies

– Galaxies often collide and get even more complicated



Fun video•Move from the simple view of a galaxy forming to a more complete computer model from NASA

•How a disk galaxies gets created

31

https://www.youtube.com/watch?&v=_Ssc1GsqHds



Another fun video

32

Andromeda tied to the rocksSimulation of a future

collision between Andromeda and the Milky Way, where the two would create a combined galaxy

http://people.physics.tamu.edu/toback/109/Video/andromeda.avi



Move from what galaxies look like and

how they form to WHEN galaxies form in the history of the

Universe33



When?• Oldest observed galaxies appear

about 500 million years after the bang

• Do we understand why this is? Use computer simulations to see when, after the Big Bang, galaxies form

• It turns out that if the Universe had exactly the same temperature everywhere it would take more than a hundred billion years to get even one galaxy

• What????



Reason things might clump earlier?

•Clearly galaxies DID form before that, so SOMETHING must have caused them to start earlier

•Example of possible answer: If the temperature weren’t perfectly uniform then we could get clumping earlier

•Go back to our trampoline analogy



Kids on a TrampolineThe galaxies form shortly after we

get that first big dent in space time

• If we start with all the kids equally spaced, then it will take longer to get that first collision

• If two of the kids happen to start slightly nearer each other, then those two are more likely to get a collision sooner and create the first dent sooner



Quantum Mechanics• It turns out that when the

Universe is really small, the effects of Quantum Mechanics can have a big effect on the smoothness of the Universe

•Can cause small variations in the temperature at different places in space–Scientists gave this a cool name: Quantum fluctuations



So What? •Different Temperature

Variation in the amount of matter in different places

•A region with slightly more matter is more likely to be the place where matter clumps

•Thus, Quantum Fluctuations in the Early Universe could cause Galaxy formation to occur earlier in time



How would we look for this?•How do we look at the temperature in the Universe?

•Study the Cosmic Background Radiation temperature distribution

•Any variations in different directions?



Look for Variation in the Cosmic Background Radiation

Look at the full sky in a single

map

Stretch out a sphere onto a

flat page

Temperature Map (i.e, different colors

correspond to different temperatures)

Incredibly Uniform, but are

there small variations?



Exactly the same everywhere?

•Subtract off the same amount everywhere

•What are we left with? The overall temperature is 2.728 degrees Kelvin

The variation is very small

T = 3.353 mK



Hotter and Colder?Colder here? Hotter here?

T = 3.353 mK



What if we’re moving?



Better ExplanationDoppler effect of our speed relative to the rest frame of the photon background

Earth is going around the sun at ~30 km/sec and the solar system is moving around the Milky Way at ~250 km/sec

Moving toward this direction

Moving away from this direction



The Cosmic Background Radiation

Combining Quantum Mechanics and General Relativity predict where the galaxies form AND

how long it takes

Subtract off all the

known effects

and look for

“Variations”

Lots of small

fluctuations (Spots)

Everywhere



For Next Time – L21• Reading:


– Unit 4 Revision (if Desired), Stage 2: Due before class Wednesday

– Unit 5, Stage 2: Due before class Wednesday• End-of-Chapter Quizzes:

– Chapter 15 (if we finished Chapter 15, else just 14)• Papers:

– Paper 2 Revision (if desired), Stage 2: due before Class Wednesday

– Paper 3, Stage 2: due before class Wednesday• Honors Paper:

– Stages 1 & 2 must be approved explicitly– Final paper due on the last day of class



Full set of Readings So Far•Required:–BBBHNM: Chaps. 1-16

•Recommended:–TFTM: Chaps. 1-5–BHOT: Chaps. 1-7, 8 (68-85), 9 and 11 (117-122)–SHU: Chaps. 1-3, 4(77-93), 5(95-114), 6, 7 (up-to-page 159) –TOE: Chaps. 1-347



Clicker QuestionOrder the following in the order of highest

required energy to lowest required energy

A.Breaking apart a ProtonB.Breaking apart a helium nucleiC.Breaking an electron out of a hydrogen

atoma) A>B>Cb) B>A>Cc) B>C>Ad) C>A>Be) C>B>A

49



Clicker QuestionHow far back in time can we “see” (clear

line of sight from light) when we look into space?

a)To ~0.5 billion years after the bang (time of creation of the first stars)

b)To ~250,000 years after the bang (time of “recombination”, creation of atoms)

c)To ~3 minutes after the bang (creation of heavy nuclei)

d)To ~microsecond after the bang (creation of protons)

50



Clicker QuestionWhy can we only see so far

back into space? a)Because before

recombination the light in the universe was scattering off of the charged particles

b)Because there are too many things in the way which block our ability to see

51



Dark Matter in GalaxiesFinished looking at the

things that produce light we can see in a Galaxy

Move to the parts which have most of the mass

Since Dark Matter doesn’t interact much, expect it to

engulf the Galaxy



53

The Planets and the SunGeneral Relativity does a good job of predicting the planets path around the sun assuming virtually all the mass of the Solar system is located at the Sun– Only small

influence due to the small masses of the other planets



Dark Matter in Galaxies• Dark matter is a BIG part of this story

because there is ~5 times more mass in the Universe in dark matter than in atoms

• Important properties of Dark Matter:– Massive – Neutral– Doesn’t interact much– Not sure when it shows up in the

Universe, but we think it was before protons could form

54



Prep For Next Time – L22•Note: May change depending on how far we get in lecture•Reading:–BBBHNM: All reading through Chapter 17

•Pre-Lecture Reading Questions:–All reading questions through 17

•End-of-Chapter Quizzes:–If we finished Chapter 15 then end-of-chapter quiz 15 (else just through Chapter 14)



Papers - 22

56

•Papers:–Paper 0: Grades posted. Check to see that you got the correct grade.

–Paper 1 Revision: No known problems–Paper 2: •Bad Rubric fixed (everyone given credit for low-quality calibration)

•Finished re-grades–Paper 2 Revision: Opened a new version. Need to resubmit ONLY if you want. Was due before class. Let me know if you need it re-opened

–Paper 3: Text was due today before class



Prep for Next time – L23•Reading:–Chapter 18

•Pre-Lecture Reading Questions:–Chapter 18

•End-of-Chapter Quizzes:–Chapter 15 (Already Done)

•Papers:–Paper 2 Revision: Was due before class today. Let us know if you were mis-graded

–Paper 3: Calibrations, reviews and Self-assessment due Wednesday before class



Prep For Next Time – L10•Note: May change depending on how far we

get in lecture•Reading:–BBBHNM: All reading through Chapter 18

•Reading Questions:–All reading questions through 18

•eLearning Quizzes:–If we finished Chapter 15 then end-of-chapter quiz 15 (else just through Chapter 14)

•Papers:–Paper 3 revisions (if desired) due before class on Tuesday





– Unit 5 Revision (if desired): Stage 1 due Monday

• End-of-Chapter Quizzes:– Chapter 15 (if we finished Chapter 15, else

just 14)• Papers:

– Paper 3 Revision (if desired): Will be opened after any regrade requests

• Honors Papers:– (Stage 2)– Final paper due on the last day of class





– Unit 5 Revision (if desired): Stage 1 due Monday

• End-of-Chapter Quizzes:– Chapter 15 (if we finished Chapter 15, else

just 14)• Papers:

– Paper 3 Revision (if desired): Stage 1 due Wednesday

• Honors Papers:– (Stage 2)– Final paper due on the last day of class



Prep for Today (Is now due) – L20

• Reading:– BBBHNM 15

• Reading questions:– Chapter 15

• End-of-Chapter Quizzes:– Chapter 14

• Paper Stuff– Paper 2 Revision: Text was due

already. Calibrations and Review are due Monday

– Paper 3: Text was due already. Calibrations and Review due Monday



Prep for Today (Is now due) – L21

• Reading:– BBBHNM 16

• Reading questions:– Chapter 16

• End-of-Chapter Quizzes:– Chapter 14

• Paper Stuff– Paper 2 Revision: Calibrations and

Review were due before class– Paper 3: Calibrations and Review

were due before class



Prep for Next Time – P20

63

• Reading– BBBHNM 16

• Reading questions– Chapter 16

• End-of-Chapter Quizzes– If we finished Chapter 15 then end-

of-chapter quiz 15 (else just 14) • Paper Stuff

– Paper 2 Revision: Text was due already. Calibrations and Review are due Monday

– Paper 3: Text was due already. Calibrations and Review due Monday



Prep for Next Time – P21

64

• Reading– BBBHNM 16

• Reading questions– Chapter 16

• End-of-Chapter Quizzes– If we finished Chapter 15 then end-

of-chapter quiz 15 (else just 14) • Paper Stuff

– Paper 2 Revision: Calibrations and Review were due before class

– Paper 3: Calibrations and Review were due before class



Billions of Years go by…•As the regions get smaller, they spin faster and faster

•Eventually, when it comes into a type of equilibrium, gravity can’t pull it in any further and the atoms stop speeding up – Kinda like the planets

going around the sun



Some Time Passes

The Transition From a “Charged” Universe to a “Neutral” Universe



A Neutral Universe• After the electrons and protons

combine to form atoms the Universe is almost completely neutral i.e., neutrally charged

• Why is this so important? All the particles in the Universe stop attracting each other due to their electric charge–Not completely true, just true

outside the atoms –Basically can ignore electric

charge from here on out



Subtract FurtherSince we understand the Doppler effect we can subtract if off to see what’s left Remember:

Overall temperature is 2.728 degrees

KelvinNow looking at

VERY VERY small variations

Extra light from the Milky way,Subtract this off also…

T = 18K



How it all ends up…

An example galaxy like our own

This explains why some galaxies •Look mostly flat•Have a halo•Bulge at the center…



For Next TimeTopics• Galaxy Formation Done• Stars Next• Black Holes After thatReading for Next time:

BBBHNM: Chap 16Full reading for Unit 5:• BBBHNM: Chaps. 1-17• TFTM: Chaps. 1-5• BHOT: Chaps. 1-7, 8 (68-85), 9 and 11 (117-

122)• SHU: Chaps. 1-3, 4(77-93), 5(95-114), 6, 7 (up-

to-page 159) • TOE: Chaps. 1-3Lecture prep: Turn in on eLearning

Two questions from Chapter 16 you want to know the answer to



Papers 1 and 2•Paper 1 and 2 grades are posted on eLearning

•Can’t get to the Paper 2 grading anymore–If you would like the opportunity to re-submit Paper 2 I’ll open it for you.

71



Papers 3 and 4• Paper 3: –Due Wed. March 24th before

class–Calibrations and grading due on

Friday at noon–Now open

• Paper 4:–Will be assigned after we start

Chapter 1772



Other Stuff•Elearning:–Unit 3 now due–Unit 4 now due–Unit 5 in progress

•Make sure you pick up the latest version of the online textbook!!!–Been updating it all semester

73



Look for variation in the Cosmic Background Radiation

Full sky in a single map

Stretch out a sphere onto a flat

page

Temperature Map

Incredibly Uniform, but are

there Small Variations?



The Reading So Far and For Unit 5

Reading for Unit 5:• BBBHNM: Chaps. 15-17• SHU: 4(87-93)• TOE: 3• BHOT: 8(76-85)Full reading through Unit 5:• BBBHNM: Chaps. 1-17• TFTM: Chaps. 1-5• BHOT: Chaps. 1-7, 8 (68-85), 9 and 11

(117-122)• SHU: Chaps. 1-3, 4(77-93), 5(95-114), 6,

7 (up-to-page 159) • TOE: Chaps. 1-3



Papers 1 and 2• Done with grades for both

– Graded unfairly? Let us know!– Want to do better? We can help!

• Want to revise Paper 2?– CPR now open, due Friday at noon– You are required to do the

calibrations for the new papers– You are required to do the reviews

for your peers– Overall grade will reflect both

original paper and the revision76



Writing AssignmentsShort Assignments 1 & 2

•Re-do’s are still possible. Want to revise again? Talk to me.

eLearning:Unit 4 now Need to be working on Unit 5



Some Time

Passes

Evolution of the Early Universe

Electrons

Protons

Photons

Photons

Atoms



The Story of Galaxy Formation

After the Big Bang we just had lots of stuff floating around in space•Can think of it as a giant tank of gas



Papers AFTER Paper 2Two options1.Two short papers like the first one

• One on Black Holes (due mid Nov)

• One on Dark Matter (due last day of class)

2.Research Paper• If you want this option you must

get Stage 0 approved ASAP •Was due last week

• Stage 1 due Thurs Nov 5th • Final paper due the last day of

class, Tuesday Dec 8th



So What?• Ok... New idea of galaxy formation. Lots of kids

jumping on a trampoline, not just straight up and down, but in random directions. Each time they hit the ground they create a little dent in the trampoline. Sooner or later two of the kids, because they will get near each other (perhaps because the dents make them more likely to get near each other) will hit each other and fall to the trampoline itself and create a big dent. The other kids jumping near that dent are now more likely to be bounced towards the center (because of the indentation) and collide with the other kids making an even bigger dent. Eventually, all the kids that are nearby the dent will be located in the same place.

• If we start with all the kids equally spaced, then it will take longer to get that first big collision. If two of the kids start nearer each other, then we're more likely to get a collision sooner and get all the kids at the big dent sooner.



Tigers in a JungleLet’s say we have a jungle with a

number of hungry tigers looking for food

If a tiger finds food they will get bigger and be more effective at hunting

If they don’t find food, they won’t grow and will starve, maybe get eaten by another tiger

Since there is only so much food, it’s just a matter of time before we are left with a few well-fed tigers



Not all Tigers are Located Equally

• Tigers nearer the food:– Will get to eat slightly sooner – Will be more energetic sooner, can go

hunting sooner and be a more effective hunter sooner

more likely to bigger quicker and thrive

• Tigers farther from the food:– Will be longer until they eat and

become effective hunters– Less food available if they get there

later more likely to die



Tigers in the Universe• If all the Tigers are equally spaced

then it will take longer, on average, before all the food is gone and we’re left with a few well-fed tigers

• If there are “fluctuations” then some of the Tigers will start closer and have an advantage over other tigers it will take less time to have a Universe with a few well-fed tigers



Where is the party?• How long it takes to get a good size Friday

night party can depend critically on how many cute people there are at the beginning of a party

• Scenario 1) If a bunch of cute people happen to be at same place early in the night won’t take long before LOTS of people will be attracted to that party

• Scenario 2) If all the cute people are evenly scattered all over then people who get to a party might leave to see if there are more cute people somewhere else Will take longer before everyone settles on a party and stays there

• Bottom line: Takes much less time to get a set of good sized parties if the number of cute people isn’t exactly uniform




The famous results from the WMAP satellite experiment



Look at the SpotsLook at the average separation of the spots • Probes the geometry of space-time

– Not a simple relationship between the separation of the spots and the geometry of space time

• Essentially:– Lots of Mass (large density) Lots of

clumping of matter Closed Universe– Medium amount of Mass (medium density)

Some clumping Flat Universe– Small amount of Mass (small density)

Small clumping Open Universe• Model the different possibilities with a

computer



Ok… The Ripples are WHERE the

galaxies form, but HOW do they form?



Wait a Billion YearsAfter less than ~1 billion years, galaxies and the first stars form

Formation of the first stars



Today’s Lecture•Overview of the story•The Cosmic Background Radiation data and why we believe in our models of Galaxy formation•Example of Galaxy Formation



Schedule from Here on Out•Mon Nov 10th: 22nd lecture (today): Galaxy

Formation– 1 page Research topic proposal due, must be

approved– Rest of the semester reading due

•Wed Nov 12th: 23rd lecture: Stars– Early version of Short Paper 2 due if you

want comments back early•Mon Nov 17th: 24th lecture: Black Holes•Wed Nov 19th: 25th lecture: Inflation•Mon Nov 24th: 26th lecture: Dark Energy•Wed Nov 26th: No class

– Research paper and 2nd short paper due at midnight

– Day before Thanksgiving. Class cancelled•Dec 1st: No classes redefined day •Dec 3rd: Reading period, no classes •Dec 8th: Finals week, no final



Looking for RipplesTo an excellent degree of precision

the temperature of the photons in the Universe today is incredibly uniformGives us

confidence that our story of the Big Bang and the Evolution of the Universe is correct



Hotter and Colder?Colder here? Hotter here?



Perfectly Flat?Subtract off the same amount everywhere

The overall temperature is 2.728 degrees Kelvin

The variation is very small



Doppler EffectTake into account our relative speed to the rest frame of the photon background

Earth is going around the sun at 30 km/sec and the solar system is rotating around the Milky Way at 250 km/sec

Moving in this direction

Moving away from this direction



Subtract FurtherSince we understand the Doppler effect we can subtract if off to see what’s left Remember:

Overall temperature is 2.728 degrees

KelvinNow looking at

VERY VERY small variations

Extra light from the Milky waySubtract this off also…



Large Scale Structure

Distribution of bright galaxies in the Virgo region indicates the Virgo cluster and presence of more distant, larger scale structure



Large Scale Structure (2)

A large survey of distant galaxies

shows the largest

structures in the universe:Filaments and

walls of galaxy

superclusters, andvoids,

basically empty space.



What if we’re moving?




The Famous COBE satellite map of the all-sky structure of the Cosmic

Background Radiation



•Add pictures from Seeds on whether we believe the structure formed first and then galaxies formed

•Or if the galaxies formed and then combined to create structure



The Growth of Clusters of Galaxies

Structures in the Universe could have developed in

two fundamentally different ways:

a) Small structures (galaxies) could have developed first, then

clustering into larger and larger structuresb) The largest structures

(superclusters, voids) could have developed first, then breaking up into smaller

and smaller units.The latter scenario seems to be favored by observational

evidence.



Looking Back at the Early Universe

The more distant the objects we observe, the further back into the past of the universe we are looking



BHOT 7 cont..,• New CMB results: tiny ripples in the

CMB can be used as an indicator of the large-scale geometry of the universe and they appear to indicate that the universe is flat after all

• Since there doesn’t seem to be enough matter and dark matter to account for this, physicists have postulated the existence of another as yet undetected substance to explain it

• Dark Energy• More on tall this stuff later…

Supernovae results…



TFTM 3 cont… •WMAP Pictures on variation in

the temperature? •Some cool numbers: Earth is

going around the sun at 30 km/sec and the solar system is rotating around the Milky Way at 250 km/sec.

•Fix this number: 1 billion photons per nuclear particle in the average contents of the universe



•The three WMAP pictures…–Flat–Dipole–Variation



• Slide 29 Maps based on 53 GHz (5.7 mm wavelength) observations made with the DMR over the entire 4-year mission (top) on a scale from 0 - 4 K, showing the near-uniformity of the CMB brightness, (middle) on a scale intended to enhance the contrast due to the dipole described in the slide 19 caption, and (bottom) following subtraction of the dipole component. Emission from the Milky Way Galaxy is evident in the bottom image.



•This is some text…



•Eventually, when the region got small enough it would be spinning fast enough to balance the attraction of gravity to balance the attraction of gravity and in this way, we believe, disk-like rotating galaxies were born

•Others would form other times of galaxies like elliptical galaxies



SHU 5 cont…•Pictures of the ripples•Page 107•COBE launched in 1989 (Nobel prize for this in 2006),

•Picture on Page 112

big bang, black holes, no math astr/phys 109 dr. david toback lecture 20 & 21

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